Fluidized bed cooler for electronic components

ABSTRACT

A fluidized bed cooler comprises a blower and a heatsink with a base and heat exchanging means. The blower comprises an electric drive with a stator and a rotor, an impeller and a casing with blower inlet and outlet. The base made as a heat spreader with a plate and provides a thermal contact with the electronic components and the heat exchanging means. The heat exchanging means are surrounded by a housing thus forms a fluidized bed chamber with inflow and outflow side openings. The fluidized bed chamber partially filled up with particulate solids and covered from both openings by intake and outtake grilled structures. The blower hydraulically connected by the inlet with the outflow side opening, so cooling gas flows through the inflow side opening, the fluidized bed chamber thus fluidizing the particulate solids, the outflow side opening, the blower inlet, the impeller and the blower outlet.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority of U.S.Provisional Patent Application No. 60/615,004, filed 10/02/2004 forEdward Lopatinsky and Lev Fedoseyev the entire content of which isincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to heat exchange apparatusesusing fluidized bed technology. More particularly, the present inventionrelates to active type coolers for cooling of electronic devices. Thepresent invention is particularly, but not exclusively, useful forcooling systems for regulating the temperature of electronic componentsof desktop computers.

BACKGROUND OF THE INVENTION

The regulation of the temperature due to heat generated inside thehousing of an electronic device is an important consideration during thedesign of an electronic device. Cooling is important because if leftunchecked, heat can cause electronic devices to malfunction during useor lead to premature device failure. As improvements in processor sizeand speed occur, the amount of heat generated by the larger and fasterprocessors also increases. Additionally, improved processors requirelarger power supplies and auxiliary components that generate increasedamounts of heat and require improved systems for heat removal.

Another factor that aggravates the need for improved heat removalcooling systems is the trend towards making computing devices smaller.The trend toward smaller electronic devices having larger, fasterprocessors renders the traditional heat removal cooling systemsinadequate for several reasons.

In order to enhance the cooling capacity of a cooling device, anelectrically powered blowers of different types such as axial, radial orcrossflow are often mounted within or on top of a heatsink of thecooling device. In operation, the blower forces air to pass over fins ofthe heatsink, thus, cooling the heatsink by enhancing the heat transferfrom the fins into the ambient air.

There are known devices of these types. For example, U.S. Pat. No.6,698,505 “Cooler for an Electronic Device” comprises a crossflowblower, No. 6,152,214 “Cooling Device and Method” comprises an axialblower and No. 6,244,331 “Heatsink with Integrated Blower for ImprovedHeat Transfer” and No. 6,664,673 “Cooler for Electronic Devices”comprise a radial blower.

Due to the modern requirements for cooling devices, especially inrespect to a combination of the thermal efficiency and an availablespace, the further enhancement of the cooling efficiency providing bythe increasing of the blower supplied power (airflow increasing) and/orby the sufficient developing of the heat exchanging surface of theheatsink.

However, mentioned increasing of the supplied power and the heatexchanging surface became in contradiction with the modern requirementsfor cooling devices. On the one hand, according to the requirements thesupplied power is limited. And on the other hand, the increasing of theheat exchanging surface of the heatsink leads to the increasing of thevolume and/or mass properties of the cooling devices and exceed thespace limitations.

The other way to increase sufficiently the thermal efficiency of coolingdevices is the use one of heat exchange intensification methods such asfluidized bed technology.

The fluidized bed (including miniaturized) technology is widely usedcommercially in chemical, pharmaceutical, food and other fields ofindustry. Usually fluidized bed technology used for drying, coating,mixing and heating/cooling a product powder.

There are known devices and apparatuses using fluidizing bed technology,for example, U.S. Pat. No. 5,954,000 “Fluid Bed Ash Cooler”, No.6,214,065 “Method of Operating a Fluidized Bed Reactor System, andFluidized Bed Reactor System” and No. 6,451,274 “Depleted UF₆ ProcessingPlant and Method for Processing Depleted UF_(6”.)

All mentioned devices comprise a fluidized bed chamber partially filledup with particulate solids and a source of airflow. When an air ispassed upwards through a bed of particles a point is reached when theupward drag force exerted by the air on the particles is equal to theapparent weight of particles in the bed. At this point the particles arelifted by the air, the separation of the particles increases, and thebed becomes fluidized. But, there are non known designs of coolers forelectronic components using fluidized bed technology.

It would be desirable for the given space provide the fluidized bedcooler for electronic components that would overcome these problemsassociated with the contradiction between the necessity of furtherenhancement of the cooling efficiency of cooling devices and compliancewith the space limitations at the same time.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide afluidized bed cooler for electronic components, which is capable toimprove significantly the thermal efficiency of cooling devices.

In order to achieve this task, the fluidized bed cooler for electroniccomponents comprises a blower and a heatsink with a base and heatexchanging means. The blower comprises an electric drive with a statorand a magnetized rotor, an impeller and a casing with blower inlet andoutlet. The base is made as a heat spreader with a plate and providing athermal contact with the electronic components and the heat exchangingmeans. The heat exchanging means are surround by a housing thus forms afluidized bed chamber with inflow and outflow side openings. Thefluidized bed chamber partially filled up with particulate solids andcovered from both openings by intake and outtake grilled structures. Theblower hydraulically connected by the inlet with the outflow sideopening, so cooling gas flows through the inflow side opening, thefluidized bed chamber thus fluidizing the particulate solids, theoutflow side opening, the blower inlet, the impeller and the bloweroutlet in a series way.

The heat exchanging means are spaced apart from each other at a distanceof at least 20 mean sizes of the particulate solids.

There are two embodiments of the present invention. First, heatexchanging means may be made as parallel vertical located finssurrounding by a box-shaped housing. For this embodiment there are twooptions of the base plate location. According to the first option theplate is located horizontally at a bottom part of the cooler thusserving for horizontal located electronic components. And, according tothe second option, the plate is located vertically at a side part of thecooler thus serving for vertical located electronic components.

According to the second embodiment of the present invention, the heatexchanging means are made as radial vertical located fins surrounding bya cylinder-shaped housing. There are two options of the base platelocation, also. First, the plate is located horizontally at a bottompart of the cooler thus serving for horizontal located electroniccomponents. And second, the plate may locate vertically at a side partof the cooler thus serving for vertical located electronic components.

The heat exchanging means and the housing may further compriseelectro-magnetic coils with a controller creating an alternating motiveelectromagnetic field and the particulate solids are made frommagnetizable material thus the particulate solids realizing arecirculation motion inside the fluidized bed chamber.

The foregoing and other objectives, features and advantages of theinvention will be more readily understood upon consideration of thefollowing detailed description of the invention, taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view showing the fluidized bed cooleraccording to the first embodiment for horizontal located electroniccomponents.

FIG. 1A is a bottom perspective view of FIG. 1.

FIG. 2 is a top perspective view of the fluidized bed cooler accordingto the first embodiment with removing of a part of the box-shapedhousing showing a part of the fluidized bed chamber at the beginning ofthe operation.

FIG. 2A is the same of FIG. 2 during the operation.

FIG. 3 is an exploded view of FIG. 1.

FIG. 4 is a top perspective view showing the fluidized bed cooleraccording to the first embodiment for vertical located electroniccomponents.

FIG. 4A is a bottom perspective view of FIG. 4.

FIG. 5 is a top perspective view of the fluidized bed cooler accordingto the first embodiment with removing of a part of the box-shapedhousing showing a part of the fluidized bed chamber at the beginning ofthe operation.

FIG. 5A is the same of FIG. 5 during the operation.

FIG. 6 is an exploded view of FIG. 4.

FIG. 7 is a top perspective view showing the fluidized bed cooleraccording to the second embodiment.

FIG. 7A is a bottom perspective view of FIG. 7.

FIG. 8 is a top perspective view of the fluidized bed cooler accordingto the second embodiment with removing of a part of the cylinder-shapedhousing showing a part of the fluidized bed chamber at the beginning ofthe operation.

FIG. 8A is the same of FIG. 8 during the operation.

FIG. 9 is an exploded view of FIG. 7.

FIG. 10 is an enlarged top perspective view shoving a part of thefluidized bed chamber with electromagnetic coils creating arecirculation motion of particulate solids.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiment of the present invention will be described indetail below with reference to the accompanying drawings.

FIGS. 1-10 show embodiments of the present invention.

The fluidized bed cooler I for electronic components 2 (FIGS. 1-9)comprises a blower 3 and a heatsink 4. The heatsink 4 comprises a base 5and heat exchanging means 6. The blower 3 comprises an electric drive 7with a stator and a magnetized rotor (not shown), an impeller and acasing 11 with blower inlet 12 and outlet 13.

The impeller 10 is made as a radial type impeller, thus the blower 3 isthe radial type blower. This type of the blower 3 is the most effectivefor creating a required pressure to support the fluidized bed process.The electric drive 7 may be used of any conventional type, for examplebrushless DC flat electric motor. The base 5 is made as a heat spreader14 with a plate 15 and provides a thermal contact with the electroniccomponents 2 and the heat exchanging means 6. The heat exchanging means6 are surrounded by a housing 16 thus forms a fluidized bed chamber 17with inflow 18 and outflow 19 side openings. The fluidized bed chamber17 partially filled up with particulate solids 20 and covered from bothopenings 18 and 19 by intake 21 and outtake 22 grilled structures. Theblower 3 hydraulically connected by the inlet 12 with the outflow sideopening 19, so cooling gas flows through the inflow side opening 18, thefluidized bed chamber 17 thus fluidizing the particulate solids 20(FIGS. 2A, 5A and 8A), the outflow side opening 19, the blower inlet 12,the impeller 10 and the blower outlet 13 in a series way.

For the best fluidized bed process the heat exchanging means 6 arespaced apart from each other at a distance of at least 20 mean sizes ofthe particulate solids 20. The material of the particulate solids 20 isnot very important and may be sand, for example.

There are two embodiments of the present invention. First, heatexchanging means 6 may be made as parallel vertical located fins 23surrounding by a box-shaped housing 27 (FIGS. 1-6). For this embodimentthere are two options of the base plate 15 location. According to thefirst option (FIGS. 1-3) the plate 15 is located horizontally at abottom part of the cooler 1 thus serving for horizontal locatedelectronic components 2. And, according to the second option (FIGS.4-6), the plate 15 is located vertically at a side part of the cooler 1thus serving for vertical located electronic components 2.

According to the second embodiment of the present invention (FIGS. 7-9),the heat exchanging means 6 are made as radial vertical located fins 28surrounding by a cylinder-shaped housing 29. There are two options ofthe base plate 15 location, also. First, the plate 15 is locatedhorizontally at a bottom part of the cooler 1 thus serving forhorizontal located electronic components 2 (FIGS. 7-9). And second, theplate 15 might locate vertically at a side part of the cooler 1 thusserving for vertical located electronic components 2 (not shown).

For both embodiments the heat exchanging means 6 and the housing 16 mayfurther comprise electromagnetic coils 30 (FIG. 10) with a controller(not shown) creating an alternating motive electromagnetic field and theparticulate solids 20 are made from magnetizable material thus theparticulate solids 20 realizing a recirculation motion inside thefluidized bed chamber 17.

The fluidized bed cooler I for electronic components 2 operates in thefollowing way. When an electric power supplied to the stator 8 of theelectric drive 7, the alternative electro-magnetic field is created.This electromagnetic field controlled by the controllers (not shown onFigs.) interacts with a magnetic field created by the magnetized rotor9. In result of this interaction the magnetized rotor 9 and, thereforethe impeller 10 of the blower 3, starts to rotate. Cooling gas startsmoving and flow through the fluidized bed chamber 17 thus fluidizing theparticulate solids 20. Heat generated by electronic components 2transfers to the base 5 due its thermal contact and spreads to the heatexchanging means 6. Cooling gas flow the heat exchanging means 6 and theintensive process of heat exchange take place.

Well known, that during the fluidized bed process a heat exchangecoefficient (heatsink-cooling gas) is more than 10 times in comparisonwith the same parameter for known coolers for electronic components. Atthe same time, the fluidized bed cooler according to the presentinvention in relation to the particulate solids size require morespacing between the heat exchanging means, at least 5 times incomparison with known coolers for electronic components. Therefore, forthe same constrains comparative to conventional technology, includingavailable space, mass etc. the fluidized bed cooler providing at leastdouble in thermal efficiency.

1. A fluidized bed cooler for electronic components comprising: a blowerand a heatsink comprising a base and heat exchanging means, wherein (i)said blower comprising an electric drive with a stator and a magnetizedrotor, an impeller and a casing with blower inlet and outlet; (ii) saidbase being made as a heat spreader with a plate and providing a thermalcontact with said electronic components and said heat exchanging means;(iii) said heat exchanging means being surrounded by a housing thusforming a fluidized bed chamber with inflow and outflow side openings;(iv) said fluidized bed chamber partially being filled up withparticulate solids and being covered from said both openings by intakeand outtake grilled structures; (v) said blower hydraulically connectedby said inlet with said outflow side opening, so cooling gas flowsthrough said inflow side opening, said fluidized bed chamber thusfluidizing said particulate solids, said outflow side opening, saidblower inlet, said impeller and said blower outlet in a series way. 2.The fluidized bed cooler as claimed in claim 1, wherein said heatexchanging means being spacing apart from each other at a distance of atleast 20 mean sizes of said particulate solids.
 3. The fluidized bedcooler as claimed in claim 1, wherein said heat exchanging means beingmade as parallel vertical located fins surrounding by a box-shapedhousing.
 4. The fluidized bed cooler as claimed in claim 3, wherein saidplate being located horizontally at a bottom part of said cooler thusserving for horizontal located electronic components.
 5. The fluidizedbed cooler as claimed in claim 3, wherein said plate being locatedvertically at a side part of said cooler thus serving for verticallocated electronic components.
 6. The fluidized bed cooler as claimed inclaim 1, wherein said heat exchanging means being made as radialvertical located fins surrounding by a cylinder-shaped housing.
 7. Thefluidized bed cooler as claimed in claim 6, wherein said plate beinglocated horizontally at a bottom part of said cooler thus serving forhorizontal located electronic components.
 8. The fluidized bed cooler asclaimed in claim 6, wherein said plate being located vertically at aside part of said cooler thus serving for vertical located electroniccomponents.
 9. The fluidized bed cooler as claimed in claim 1, whereinsaid heat exchanging means and said housing further comprisingelectromagnetic coils creating an alternating motive electromagneticfield and said particulate solids being made from magnetizable materialthus said particulate solids realizing a recirculation motion insidesaid fluidized bed chamber.